WO2019072567A1 - Capteur pour un dispositif de résonance de spin nucléaire - Google Patents

Capteur pour un dispositif de résonance de spin nucléaire Download PDF

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Publication number
WO2019072567A1
WO2019072567A1 PCT/EP2018/076125 EP2018076125W WO2019072567A1 WO 2019072567 A1 WO2019072567 A1 WO 2019072567A1 EP 2018076125 W EP2018076125 W EP 2018076125W WO 2019072567 A1 WO2019072567 A1 WO 2019072567A1
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WO
WIPO (PCT)
Prior art keywords
sensor
magnetic
magnetic field
planar magnet
segments
Prior art date
Application number
PCT/EP2018/076125
Other languages
German (de)
English (en)
Inventor
Reiner Krapf
Ulli Hoffmann
Michael Ledwig
Stefan Wintzheimer
Toni DRIESLE
Original Assignee
Robert Bosch Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
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Application filed by Robert Bosch Gmbh filed Critical Robert Bosch Gmbh
Priority to CA3078574A priority Critical patent/CA3078574A1/fr
Priority to US16/652,832 priority patent/US11143725B2/en
Priority to EP18779355.9A priority patent/EP3695213A1/fr
Publication of WO2019072567A1 publication Critical patent/WO2019072567A1/fr

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
    • G01R33/34—Constructional details, e.g. resonators, specially adapted to MR
    • G01R33/341—Constructional details, e.g. resonators, specially adapted to MR comprising surface coils
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N24/00—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
    • G01N24/08—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using nuclear magnetic resonance
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/30—Sample handling arrangements, e.g. sample cells, spinning mechanisms
    • G01R33/307—Sample handling arrangements, e.g. sample cells, spinning mechanisms specially adapted for moving the sample relative to the MR system, e.g. spinning mechanisms, flow cells or means for positioning the sample inside a spectrometer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
    • G01R33/34—Constructional details, e.g. resonators, specially adapted to MR
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/3808—Magnet assemblies for single-sided MR wherein the magnet assembly is located on one side of a subject only; Magnet assemblies for inside-out MR, e.g. for MR in a borehole or in a blood vessel, or magnet assemblies for fringe-field MR
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/383—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using permanent magnets
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
    • G01R33/48—NMR imaging systems
    • G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console
    • G01R33/56—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution
    • G01R33/565—Correction of image distortions, e.g. due to magnetic field inhomogeneities
    • G01R33/56563—Correction of image distortions, e.g. due to magnetic field inhomogeneities caused by a distortion of the main magnetic field B0, e.g. temporal variation of the magnitude or spatial inhomogeneity of B0
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
    • G01R33/34—Constructional details, e.g. resonators, specially adapted to MR
    • G01R33/34007—Manufacture of RF coils, e.g. using printed circuit board technology; additional hardware for providing mechanical support to the RF coil assembly or to part thereof, e.g. a support for moving the coil assembly relative to the remainder of the MR system
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/3802—Manufacture or installation of magnet assemblies; Additional hardware for transportation or installation of the magnet assembly or for providing mechanical support to components of the magnet assembly
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/42—Screening
    • G01R33/422—Screening of the radio frequency field

Definitions

  • the invention further comprises a nuclear magnetic resonance apparatus with at least one such sensor.
  • Nuclear Magnetic Resonance is used in various engineering applications for measuring material properties.
  • the measurement principle is based on a physical effect in which the material sample to be examined is exposed to external magnetic fields and the change in the magnetization of the atomic nuclei within the material sample in response to the external
  • Magnetic fields is measured.
  • the atomic nuclei in the material sample are first aligned by means of a first magnetic field (BO field).
  • the nuclear spins of the atomic nuclei are in resonance with the first magnetic field, whereby the spins of the atomic nuclei with the so-called Larmor frequency precede the magnetic field lines (Larmor precession).
  • the material sample is subsequently exposed to a second magnetic field (B1 field) oriented orthogonally to the first magnetic field, the atomic nuclei in the first nuclear spin state can change the orientation of their spin by absorbing energy of the second magnetic field.
  • B1 field second magnetic field
  • the second magnetic field is switched off again, with the material sample still remaining exposed to the first magnetic field, an excited nuclear spin state results for the atomic nuclei with the previously deflected nuclear spins, from which they return to the energetically lower first one in a relaxation process
  • KernspinPark return in which their nuclear spins to the Magnetic field lines of the first magnetic field are aligned.
  • the relaxation process takes place by emitting electromagnetic radiation, which manifests itself in a change in the magnetic field.
  • This magnetic field change can be detected as a response signal by means of a suitable detection or measuring device 5 in the form of an antenna or coil.
  • Operating parameters of the nuclear magnetic resonance apparatus can by evaluating the amplitude and the time course of the response signal to the
  • this measuring method is optimally suitable for determining the quantity or
  • the first magnetic field in particular a static magnetic field with 15 defined properties and a second magnetic field as an electromagnetic
  • Alternating field such as a pulsed magnetic field used.
  • nuclear magnetic resonance devices are typically formed in the form of a closed cylinder. This design limits the use of the nuclear magnetic resonance apparatus, as only such material samples are measured
  • a sensor for a nuclear magnetic resonance apparatus for determining at least one material property of one in a useful volume arranged material sample provided.
  • the magnetic resonance apparatus here comprises a magnetic field generating device comprising a planar magnet arrangement for generating a static magnetic field in the
  • the nuclear magnetic resonance apparatus further comprises a measuring device for measuring a response signal based on nuclear magnetic resonance of the material sample arranged in the useful volume, comprising an electrical coil with at least one winding for generating an alternating magnetic field in the useful volume.
  • the Wcklung is arranged between two immediately adjacent magnetic poles of the planar magnet arrangement, so that the magnetic
  • Useful volume with a suitable choice of operating parameters automatically an orthogonality between the field lines of the static magnetic field and the field lines of the alternating magnetic field.
  • a usable volume extending parallel to the nuclear magnetic resonance sensor is defined, in which sufficiently good conditions for an NMR measurement are present.
  • the sensor has a flat construction. Since such a sensor does not enclose the material sample, the size of the material sample to be measured is not limited. In particular, with the aid of such a sensor it is also possible to measure flat objects, such as, for example, a house wall. In this case, due to the flat construction, the sensor can also be designed inter alia as a portable device, e.g. in the form of a hand-held device.
  • the senor is particularly compact due to the flat design.
  • Magnet arrangement a plurality of juxtaposed magnet segments each orthogonal to a second extension direction of the planar
  • Magnet arrangement aligned magnetization directions.
  • the magnet segments which are arranged directly next to one another along the first direction of extent of the planar magnet arrangement, have magnetization directions rotated relative to one another, as a result of which magnetization directions are rotated on the magnet
  • Magnet arrangement to be concentrated.
  • This arrangement which may be formed, for example, in the form of a planar or rolled Halbach array, allows a significant increase in the field strength of the static magnetic field in the useful volume.
  • the necessary high field strength can be achieved with relatively simple magnets, for example with standard magnets.
  • This arrangement also allows a particularly flexible construction of the sensor, wherein the number of magnetic poles and their position along the first direction of extent of the planar magnet arrangement can be adapted to the respective requirements.
  • the electrical coil of the measuring device comprises three juxtaposed windings whose
  • magnetic poles are each arranged between two immediately adjacent magnetic poles of the planar magnet arrangement. This construction provides an optimized arrangement of, with the help of a sufficiently homogeneous magnetic field can be generated in the effective volume. Moreover, this makes it possible to realize a relatively compact sensor module.
  • the electric coil also for measuring a nuclear magnetic resonance in the useful volume
  • the structure can be simplified because no separate coils for excitation and for detection are necessary. However, separate coils can also be used for excitation and detection.
  • the electrical coil is arranged on the front side of the planar magnet arrangement. As a result, the sensitivity of the electrical coil is increased, in particular in the detection of the response signal.
  • the electrical coil is designed in the form of a structured electrically conductive layer.
  • the electric coil can be generated for example by means of a photolithographic process, which allows a particularly high precision.
  • At least one shim coil for homogenizing the static magnetic field generated by the planar magnet arrangement in useful volume is formed in the electrically conductive layer.
  • Such shim coils are very precise Magnetic fields possible.
  • the integration of the shim coil in the electrically conductive layer allows a particularly flat design.
  • the electrical coil is designed in the form of a multiresonant coil.
  • Coil can generate or detect alternating fields with different frequencies. Furthermore, it is also possible with the multiresonant coil to measure different layers simultaneously, wherein the distinction between the individual layers can be made via a field-dependent contrast.
  • Shielding structure of an electrically conductive material having a high magnetic permeability is arranged, which the magnetic segments as
  • Shielding in front of the alternating magnetic field of the electric coil is used.
  • the inner shielding structure By means of the inner shielding structure, the alternating magnetic field generated by the electrical coil can be shielded in the area of the permanent magnets. As a result, mechanical forces are prevented, which on the permanent magnets due to the magnetic or
  • this measure can be used to correct the measuring signal
  • Measurement accuracy of the sensor can be increased.
  • an outer shielding structure made of an electrically conductive material having a high magnetic permeability is arranged, which of the electric coil as a shield against
  • the outer shielding structure allows unwanted electromagnetic influences to be applied to the magnetic shield
  • Prevent coil This can increase the accuracy of measurement. By using a material having a high magnetic permeability, an undesirable damping of the static magnetic field in the useful volume can be prevented.
  • outermost magnetic permeability By using a material having a high magnetic permeability, an undesirable damping of the static magnetic field in the useful volume can be prevented.
  • Shielding structure has resonant structures, which for targeted
  • Shielding electromagnetic interference fields with frequencies in the range of the network frequency serve.
  • a shielding structure can be produced which shields only interference signals of specific frequencies. This is particularly necessary for frequencies in the range of the network frequency, since such interference fields are common in technical applications
  • the measurement accuracy can be significantly increased.
  • Magnetic field generating device a carrier plate of a
  • Magnetic segments can be relatively easily installed and removed. This makes it possible to remove the magnetic segments, for example, for transport from the carrier plate. Furthermore, the static magnetic field can be damped by twisting or swapping the magnet segments within the carrier plate for the transport or storage of the sensor. In addition, the magnet segments can also be replaced individually, whereby an adaptation of the static magnetic field to the respective application is possible.
  • the magnet segments of the magnet arrangement is rotatably formed within the carrier plate. This makes it possible to adapt the static magnetic field by turning the individual magnet segments to the respective specifications.
  • the static magnetic field in the useful volume can be reduced by a suitable rotation of specific magnet segments, which is advantageous in particular for the storage and transport of the nuclear magnetic resonance apparatus.
  • Magnetic field generating device by juxtaposing a plurality of carrier plates in at least one of the two directions of extension of the planar magnet assembly is modular expandable. This modular design allows flexible adjustment of the sensor size along the two
  • magnetic segments are formed in an edge region of the planar magnet arrangement to generate a static magnetic field with a higher magnetic field strength than magnetic segments in a central region of the planar magnet arrangement.
  • a weakening of the magnetic field strength can be counteracted, which typically occurs in the edge regions of the magnet arrangement.
  • magnetic field strength is achieved in the edge region of the planar magnet assembly by magnetic segments having a higher magnetization and / or a greater vertical extent, as magnetic segments in the central region of the planar magnet assembly.
  • Magnet arrangement a particularly flat design of the sensor can be achieved.
  • Magnetic arrangement Magnetic segments with the maximum magnetization can be used. As a result, a significantly higher field strength in the total useful volume can be achieved overall.
  • Edge region of the planar magnet arrangement can be realized by means of standard magnets.
  • the magnetic field generating device can be particularly simple and inexpensive to build.
  • at least a part of the magnet segments of the planar magnet arrangement has a sheath made of a plastic.
  • the distance between the individual can be determined by means of the thickness of the plastic coating
  • Plastic coating better handling of the magnet segments, during installation and removal and the transport of the sensor.
  • a nuclear magnetic resonance device comprising a corresponding sensor is provided.
  • the nuclear magnetic resonance device is designed to have at least one material property of one in one
  • Effective volume arranged material sample for several measurement layers to determine independently.
  • the nuclear magnetic resonance device comprises a lifting device for adjusting the distance between the sensor and a material sample arranged in the useful volume.
  • the lifting device comprises at least one electrically and / or manually driven actuator. With the aid of such a lifting device, depth-dependent measured values can be generated in a simple manner. As a result, an accurate depth profile of the measured material sample can be created.
  • the actuator comprises a first actuator part carrying the sensor and a second actuator part arranged movably therewith with a support surface for placement on a contact surface fixedly arranged relative to the material sample.
  • the first actuator part is designed in the form of an electric motor while the second actuator part is designed in the form of a spindle driven by the electric motor.
  • a Spindle drive allows a particularly precise adjustment of the height of the sensor.
  • the lifting device comprises a plurality of actuators distributed along the circumference of the sensor. This allows a particularly stable and precise height adjustment.
  • FIG. 1 shows a sensor for a nuclear magnetic resonance apparatus comprising a magnetic field generating device with a planar magnet arrangement and a measuring device in a schematic cross-sectional representation
  • FIG. 2 is a plan view of the magnetic field generating device of the sensor with the planar magnet arrangement of FIG. 1;
  • FIG. 3 shows a schematic side view of the planar magnet arrangement with eleven magnet segments arranged side by side, each with magnetization directions rotated by 45 °;
  • Fig. 4 is a side view of a planar magnet arrangement with a in
  • Fig. 5 is a plan view schematically of the planar magnet assembly with four magnetic poles and a three coil electrical coil;
  • FIG. 6 is a plan view of an electrical coil with three developments produced by patterning an electrically conductive layer
  • Fig. 7 is a side view of the planar magnet assembly of Figure 4 and formed in the electrically conductive layer electrical coil to
  • Fig. 8 is a side view of the planar magnet assembly of Fig. 4 and the electrical coil of Fig. 7 illustrating the superposition of the magnetic fields generated by the planar magnet assembly and the electrical coil;
  • Fig. 9 is a plan view of a sensor with a three side by side
  • FIG. 10 is a plan view of a sensor with a four adjacent magnetic poles arranged planar magnet assembly and three juxtaposed windings having electrical coil.
  • 1 1 shows schematically a plan view of a planar magnet arrangement of separate magnet segments, which are arranged in the form of a 1x1 1 matrix;
  • FIG. 12 schematically shows a plan view of a planar magnet arrangement comprising a total of eleven prism-shaped magnet segments
  • FIG. 13 schematically shows a side view of a planar magnet arrangement comprising a magnet segment extending over the entire width, which has areas with differently oriented magnetization in FIG.
  • Fig. 14 schematically a cross-sectional view through a planar
  • Magnet arrangement with superposed in two planes carrier plates with magnetic segments
  • Fig. 15 is a schematic plan view of the lower support plate to illustrate the specific arrangement of the magnet segments in the lower support plate.
  • FIG. 16 schematically shows a side view of a magnetic resonance apparatus comprising a sensor and a lifting device for adjusting the
  • the nuclear magnetic resonance sensor according to the invention is characterized by a flat design, which allows an outwardly open measuring system, which can also be extended by a series of multiple sensors.
  • the flat design of the sensor is achieved by a special arrangement of permanent magnets for generating a B0 field and a special arrangement of at least one electric coil for generating a B1 field.
  • 1 shows schematically a cross section through such a nuclear magnetic resonance sensor 100.
  • the sensor 100 in this case comprises a magnetic field generating device 101 for generating a static
  • Magnetic field generating device 101 and the useful volume 200 arranged measuring device 102 for generating an excitation signal (B1 field) in the useful volume 200 and for measuring the subsequent response signal.
  • the magnetic field generating device 101 includes a planar
  • magnet segments 1211, 1212, 1213 may also have other suitable shapes, for example cylindrical or round.
  • Magnetic field generating device 101 further comprises a support plate 1 10, which serves as a matrix for receiving the magnet segments 1211, 1212, 1213.
  • the support plate 1 10 a plurality of openings 11 1, in each of which a magnetic segment 1211, 1212, 1213 is arranged.
  • the openings 1 11 define the position and orientation of the magnet segments 1211, 1212, 1213 to each other.
  • the special arrangement of the magnet segments within the magnet arrangement 120 generates a magnetic field with defined properties within a specific spatial area 200, which is arranged directly above the sensor 100 in FIG.
  • the space area 200 defines a
  • the measuring device 102 is designed in the form of a layer stack comprising a plurality of layers 161, 162, 163, 164, 165, 166, 167, 168.
  • the layer stack comprises an electrically conductive layer 164, which is preferably arranged on a carrier substrate 165, preferably a printed circuit board, such as PCB.
  • the electrically conductive layer 164 contains an electrical coil 140 with one or more windings arranged next to each other (not shown here).
  • the electrical coil 140 which was produced in the present exemplary embodiment by structuring the electrically conductive layer 164, forms an essential part of the measuring device 102.
  • the electrical coil 140 generates an alternating magnetic field (B1 field), which is in the useful volume 200 with the magnetic field of the planar magnet assembly 120 substantially orthogonally superimposed and as an excitation signal for the
  • the electrical coil 140 preferably also simultaneously forms an antenna for detecting the response signal following the excitation signal.
  • alternating field 150 for example, serve a pulsed magnetic field.
  • other time-varying electromagnetic fields can also be used as the excitation signal (B1 field).
  • the electrically conductive layer 164 may also include at least one further electrical coil, in particular a shim coil, for correcting the magnetic energy generated by the electrical coil 140 Contain alternating field.
  • further passive and active components can be arranged on the carrier substrate 165, preferably in the
  • the measuring device 102 may further comprise an outer shielding structure.
  • the shielding structure may have special structuring which serves as resonance structures for the
  • Shielding structure formed in the form of a structured metallic layer 161, which, for example, copper or another not
  • the outer shielding structure 161 is arranged on a separate carrier substrate 162.
  • the carrier substrate 162 may, for example, be in the form of a circuit board and a relatively small one
  • Carrier substrate 162 further comprises a first separation layer 163 with defined
  • the layer thickness is preferably very few
  • the measuring device 102 may further include an inner shielding structure that shields the magnet segments of the planar magnet assembly 120 from the alternating magnetic field of the electrical coil 140. With such an inner shielding structure, it is possible to prevent mechanical forces from acting on the magnet segments due to the alternating magnetic field of the electrical coil 140, which effects a falsification of the measurement signal.
  • the inner shielding structure is in the form of a thin metallic layer 168 arranged between the electrical coil 140 and the magnet segments of the magnet arrangement 120.
  • a material for the inner shielding structure 168 for example, copper or another non-magnetic metal comes into question.
  • the inner shielding structure 168 may be arranged on a separate substrate layer 167, which
  • the substrate layer 167 may consist of any suitable material, in particular a non-magnetic material, such as cardboard or hard paper. Furthermore, between the two electrically conductive layers 164,
  • a second separating layer 166 may be provided, with the help of which the exact distance between the electrical coil 140 and the inner
  • shielding structure 168 Define shielding structure 168.
  • the layer thickness of this separating layer 166 is preferably a few millimeters, for example 2 mm.
  • the separating layer 166 can be formed from any suitable material, for example a non-magnetic material.
  • the measuring device 102 shown in FIG. 1 comprises a total of eight
  • the substrate layer 162 and the release layer 163 may be formed as a common layer.
  • the separating layer 166 may also form a common layer with the substrate layer 165 and / or with the substrate layer 167 (not shown here).
  • the measuring device 102 Due to the layered structure and the small layer thicknesses of the layers 161-168, the measuring device 102 has a relatively low
  • a further separating layer 170 can be provided between the two components.
  • the separating layer 71 is preferably made of a non-magnetic material, such as an acrylic plate.
  • the acrylic plate 170 is preferably made of a non-magnetic material, such as an acrylic plate.
  • Recesses which receives the protruding from the support plate 110 areas of the magnet segments 1211, 1212, 1213.
  • the planar magnet arrangement 120 typically comprises a plurality of magnetic segments arranged side by side in a plane, the number of them and spatial arrangement may vary depending on the particular application.
  • FIG. 2 shows, by way of example, a plan view of a planar magnet arrangement 120 extending in the XY plane with a total of 121 magnetic segments 121 i, 121 n, n arranged within the carrier plate 1 10.
  • Magnetic segments 1211, 1 - 121 n, n are preferably uniform over the
  • Support plate 1 10 distributed and form in the present embodiment, a 1 1x1 1 matrix with 1 1 rows and 1 1 columns.
  • the planar magnet arrangement 120 has a total of four magnetic poles 131, 132, 133, 134, each with alternating magnetic field directions, which are indicated in FIG. 2 by dashed lines.
  • Figure 3 shows a cross section through the planar magnet assembly 120 of Figure 2 along the line 105, wherein the
  • Magnetic segments a special magnet arrangement is achieved, which corresponds essentially to a Halbach array.
  • Such a configuration of permanent magnets allows the magnetic flux to almost cancel on a first side of the magnet assembly while being amplified on the second side opposite to the first side.
  • the magnetic field 130 which is indicated schematically in FIG. 3 by means of the field lines, is mainly concentrated on the front side 103 of the planar magnet arrangement 120 facing the useful volume 200, while it on the back 104 of the planar magnet assembly 120 is relatively weak.
  • Magnetic segments 1211, 5, 12111, 5 arranged at the edge of the magnet arrangement are each rotated by 90 ° with respect to their neighbors. This reduces possible distortions of the static magnetic field 130 in the edge region 127 of the magnet arrangement.
  • the angle of rotation between adjacent magnet segments basically vary depending on the particular application. In particular, when using a larger number of separate magnetic segments, a smaller angle of rotation can be used than with a smaller number of magnetic segments. To a weakening of the static magnetic field 130 in the edge regions
  • FIG. 4 shows a corresponding planar magnet arrangement 120 with magnet segments of different height 1211, 5 - 12111, 5. Due to the compensation of the magnetic field weakening in the edge regions 127 of the magnet arrangement 120, the two outer ones have
  • Subsections 135, 137 of the static magnetic field 130 are substantially the same stronger as the central portion 136 of the static magnetic field 130. This results in a substantially homogeneous field strength of the static magnetic field 130 in the different measuring layers of
  • Useful volume 200 For reasons of clarity, only three of the useful volumes 200 defining measuring layers by means of the lines 201, 202, 203 are indicated in Figure 4. As shown here, are the
  • Measuring layers 201, 202, 203 preferably above the electrical coil 140. Due to the high homogeneity of the magnetic fields realized in the measuring layers, it is possible to measure different atomic nuclei simultaneously. It can be a Differentiation of the different atomic nuclei can be made by means of T1 / T2 relaxation.
  • Magnet assembly 120 is shown schematically in FIG. It can be seen here that the electrical coil 140 in the present exemplary embodiment comprises a total of three windings 141, 142, 143. In this case, the windings or the inner regions of the windings are each arranged between two directly adjacent magnetic poles 131, 132, 133, 134.
  • FIG. 6 shows a possible design of an electrical coil 140 with three windings 141, 142, 143 arranged next to one another, which was produced by structuring the electrically conductive layer 164 by way of example.
  • the juxtaposed windings 141, 142, 143 of the electrical coil 140 shown in FIG. 6 are in the form of partial coils, each partial coil comprising two windings in the present case.
  • the number of turns per coil may vary depending on the application.
  • a multiresonant coil different layers of the useful volume 200 can be measured simultaneously. The distinction of the different ones
  • Layers can be done by means of a field-dependent contrast.
  • a magnetic field-dependent contrast agent can be used.
  • FIG. 7 shows one of the arrangements which corresponds to the configuration from FIG. 4, in which case only the alternating magnetic field 150 of FIG
  • the magnetic alternating field 150 generated by the three partial coils 141, 142, 143 during operation has a total of three magnetic poles 151, 152, 153 on the upper side facing the useful volume 200.
  • FIG. 8 shows a superimposition of the static magnetic field 130 from FIG. 4 and the alternating magnetic field 150 from FIG. 7.
  • the two magnetic fields 130, 150 are mutually offset magnetic poles each having a magnetic pole 151, 152, 153 of the alternating magnetic field 150 is arranged substantially centrally between two immediately adjacent magnetic poles 131, 132, 133, 134 of the static magnetic field 130. Due to this special arrangement, it follows that the field lines of the two magnetic fields 130, 150 in which by the usable
  • Measuring layers 201, 202, 203 defined useful volume 200 are substantially orthogonal to each other. It can by a corresponding
  • Adjustment of the operating parameters or the configuration of an optimized for NMR measurement field distribution in the useful volume 200 can be achieved.
  • the senor 100 can also be produced in different sizes. In this case, the number of magnetic segments used may vary with the number of sub-coils. 9 shows a miniaturized version of the sensor 100 from FIG. 5.
  • the sensor 100 has a planar magnet arrangement 120 with a total of 41 41 arranged in a 7 ⁇ 6 matrix
  • the electrical coil 41 has only two turns or partial coils 141, 142.
  • FIG. 10 shows an enlarged version of the sensor 100 from FIG. 5.
  • the enlarged sensor 100 has a planar
  • Magnet assembly 21 with a total of 150 arranged in a 15x10 matrix magnet segments on.
  • the static magnetic field on the front side of the planar magnet arrangement 120 has a total of five magnetic poles 131, 132, 133,
  • the electrical coil 41 comprises a total of four coils or partial coils 141, 142, 143, 144.
  • the magnet segments of the planar magnet arrangement 120 can also be arranged without gaps against each other.
  • FIG. 11 shows a correspondingly designed planar magnet arrangement 120.
  • planar magnet arrangement basically also be generated by a juxtaposition of elongated magnetic segments.
  • FIG. 12 shows a corresponding planar one
  • Magnet arrangement 21 which comprises a total of eleven in the first Warreckungsnchtung X side by side arranged bar or rod-shaped magnet segments.
  • FIG. 13 shows a planar magnet arrangement 120 with a single magnet segment 121, which
  • immediately adjacent sections of the magnet segment 121 each have magnetization directions rotated by a certain angle.
  • Such a permanent magnet can be generated for example by sintering.
  • FIG. 14 shows a
  • Magnetization device 101 an additional support plate 1 12, which is mounted below the first support plate 1 10.
  • the second carrier plate 1 12 has only in its edge regions 127 magnetic segments 124i, s - 124ii, 5. In the central region 128 of the second carrier plate 1 12, however, no magnetic segments are present. Due to the superimposition of the magnetic fields in the edge regions 121 of the magnet arrangement one above the other
  • FIG. 15 shows a plan view of the additional carrier plate 12 of FIG. 14. It can be seen here that the additional carrier plate 12 also has additional magnet segments 124i, i-12111, 11 in a middle region in the X-direction. To better illustrate the distribution of
  • Magnet segments 124i, i - 121 n, n within the support plate 1 12 are the Openings 1 13 of the support plate 112, in which no corresponding
  • Magnetic segment is shown with a dash-dot line.
  • the static magnetic field 130 of the magnetic field generating device 101 can be modified in the desired manner. Furthermore, it is also possible to arrange the magnet segments in more than two levels one above the other.
  • the use of a carrier plate with removable magnets allows a relatively simple change of the magnet assembly. As a result, the planar magnet arrangement can basically be adapted to the respective application.
  • the static magnetic field (B0 field) by turning individual
  • Magnetic segments within the carrier plate for the transport or storage of the sensor damped or even almost completely compensated An analogous reduction of the magnetic field can be achieved by interchanging the position of individual magnet segments within the carrier plate.
  • FIG. 16 shows by way of example a nuclear magnetic resonance apparatus 300 arranged on a base plate 400.
  • the nuclear magnetic resonance apparatus 300 comprises a sensor 100 arranged within a housing 180, a housing 180 accommodating the sensor 100 and a mechanical lifting device 310 arranged on the housing for adjusting the distance between the sensor 100 and a material sample arranged underneath.
  • Essentially sensor analogous to the sensor of FIG. 4 comprises a magnetic field generation device 101 with a sensor
  • Magnetic arrangement 120 for generating a static magnetic field 130 and a measuring device 102 with an electrical coil 140 for generating an alternating magnetic field 150 In the present example, however, the sensor 100 is rotated by 180 °, so that the magnetic arrangement
  • the nuclear magnetic resonance device 300 may determine certain material properties of the bottom plate 400, which in the present example serves as a material sample. In principle, however, it is also possible to measure material samples which are arranged on or under the bottom plate 400 or inside the bottom plate 400.
  • the mechanical lifting device 310 comprises one or more manually or electrically operated actuators 320, 330, which are preferably distributed along the outer circumference of the housing 180. In particular, four actuators each arranged at the corners of the housing 180 may be provided. In the figure 16 a total of two actuators 320, 330 are shown, which are arranged on two opposite sides of the housing 180. The actuators 320, 330 are in the present
  • Embodiment arranged on the outside of the housing 180.
  • the actuators 320, 330 may be disposed within the housing 180 (not shown).
  • the actuators 320, 330 each include a first actuator part 321 connected to the housing 180 and a second actuator part 322, 332 which is movable with a bearing surface 323, 333 on the surface 410 of the bottom plate 400 serving as the material sample.
  • the actuators 320, 330 are in the
  • the second actuator part 322, 332 in each case forms an electric motor while the first actuator part 321, 331 is designed in the form of a spindle driven by the electric motor.
  • Such a construction allows a particularly fine and accurate adjustment.
  • the first actuator part 321, 331 is displaced relative to the respective second actuator part 322, 332. Coordinated movement of all the actuators results in a desired lifting movement of the sensor 100 relative to the bottom plate 400. For this reason, depth-dependent measured values can be generated with the help of the lifting device 300 in a relatively simple manner, with the aid of which a depth profile of the bottom plate 400 or one with the bottom plate 400 stationary bonded material sample can be generated.
  • the lifting device is preferably controlled by means of a suitable control device.
  • This control device may for example be an integral part of the control and evaluation of the nuclear magnetic resonance apparatus.
  • a self-sufficient control device for controlling the stroke movement of the sensor 100 is possible.
  • manually operated actuators can be used, which have, for example, a manual latching with predefined distances.
  • FIG. 16 shows further components of the nuclear magnetic resonance apparatus 300, such as e.g. the control and evaluation device or the power supply device, not shown.
  • the nuclear magnetic resonance apparatus may comprise one or more of the NMR sensors described herein.
  • a typical nuclear magnetic resonance apparatus further comprises other components, such as e.g. a tax and

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Health & Medical Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Vascular Medicine (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Signal Processing (AREA)
  • Engineering & Computer Science (AREA)
  • Radiology & Medical Imaging (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Magnetic Resonance Imaging Apparatus (AREA)
  • Investigating Or Analyzing Materials By The Use Of Magnetic Means (AREA)

Abstract

L'invention concerne un capteur (100) pour un dispositif de résonance de spin nucléaire (300) pour la détermination d'au moins une propriété de matériau d'un échantillon de matériau disposé dans un volume utile (200). Le dispositif de résonance de spin nucléaire (300) comprend : – un dispositif de génération de champ magnétique (101), comprenant un agencement plan d'aimants (120) pour générer un champ magnétique statique (130, 135, 136, 137) dans le volume utile (200), l'agencement plan d'aimants (120) présentant, sur une face avant (103) tournée vers le volume utile (200), plusieurs pôles magnétiques (131, 132, 133, 134), qui sont disposés les uns à côté des autres avec une orientation à chaque fois alternée le long d'une première direction d'extension (X) de l'agencement plan d'aimants (120) et – un dispositif de mesure (102) pour mesurer un signal basé sur la résonance de spin nucléaire de l'échantillon de matériau disposé dans le volume utile (200), comprenant une bobine électrique (140) pourvue d'au moins un enroulement (141, 142, 143, 144) pour générer un champ magnétique alternatif (150, 154, 155) dans le volume utile (200), l'enroulement (141, 142, 143, 144) étant disposé entre deux pôles magnétiques (131, 132, 133, 134) directement adjacents de l'agencement plan d'aimants (120) de telle sorte que le champ magnétique alternatif (150, 154, 155) de la bobine électrique (140) dans l'ensemble du volume utile (200) se superpose de manière sensiblement perpendiculaire au champ magnétique statique (130, 135, 136, 137) de l'agencement plan d'aimants (120).
PCT/EP2018/076125 2017-10-09 2018-09-26 Capteur pour un dispositif de résonance de spin nucléaire WO2019072567A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CA3078574A CA3078574A1 (fr) 2017-10-09 2018-09-26 Capteur pour un dispositif de resonance de spin nucleaire
US16/652,832 US11143725B2 (en) 2017-10-09 2018-09-26 Sensor for a nuclear magnetic resonance device
EP18779355.9A EP3695213A1 (fr) 2017-10-09 2018-09-26 Capteur pour un dispositif de résonance de spin nucléaire

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102017217875.2A DE102017217875A1 (de) 2017-10-09 2017-10-09 Sensor für eine Kernspinresonanzvorrichtung
DE102017217875.2 2017-10-09

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WO2019072567A1 true WO2019072567A1 (fr) 2019-04-18

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EP (1) EP3695213A1 (fr)
CA (1) CA3078574A1 (fr)
DE (1) DE102017217875A1 (fr)
WO (1) WO2019072567A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3951417A1 (fr) 2020-08-07 2022-02-09 Bruker BioSpin GmbH Capteur rmn avec un espace pour échantillon en v pour l'analyse de liquides

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102019216755A1 (de) * 2019-10-30 2021-05-06 Robert Bosch Gmbh Verfahren zum Betrieb eines NMR-Spektrometers sowie NMR-Spektrometer

Citations (4)

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Publication number Priority date Publication date Assignee Title
WO2006061618A1 (fr) * 2004-12-08 2006-06-15 University Of Surrey Agencement plan d'aimants pour resonance magnetique nucleaire
DE202006002074U1 (de) * 2006-02-08 2006-07-13 AixNMR Zentrum für Magnetische Resonanz e.V. Unilateraler NMR Sensor mit mikroskopischer Tiefenauflösung
US20100244828A1 (en) * 2007-08-31 2010-09-30 Alexander Pines Adjustable permanent magnet assembly for nmr and mri
DE102014218375A1 (de) * 2014-09-12 2016-03-17 Robert Bosch Gmbh Handmessgerät und Verfahren zu dessen Betrieb

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Publication number Priority date Publication date Assignee Title
US8237440B2 (en) * 2005-09-23 2012-08-07 University Of New Brunswick Magnetic field generator suitable for unilateral nuclear magnetic resonance and method for making same
DE102015226168A1 (de) * 2015-12-21 2017-06-22 Robert Bosch Gmbh Verwendung eines Messgeräts zur Untersuchung von Bestandteilen eines menschlichen oder tierischen Körpers
US10564237B2 (en) * 2017-04-21 2020-02-18 Massachusetts Institute Of Technology Single-sided magnets for remote nuclear magnetic resonance measurements

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006061618A1 (fr) * 2004-12-08 2006-06-15 University Of Surrey Agencement plan d'aimants pour resonance magnetique nucleaire
DE202006002074U1 (de) * 2006-02-08 2006-07-13 AixNMR Zentrum für Magnetische Resonanz e.V. Unilateraler NMR Sensor mit mikroskopischer Tiefenauflösung
US20100244828A1 (en) * 2007-08-31 2010-09-30 Alexander Pines Adjustable permanent magnet assembly for nmr and mri
DE102014218375A1 (de) * 2014-09-12 2016-03-17 Robert Bosch Gmbh Handmessgerät und Verfahren zu dessen Betrieb

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3951417A1 (fr) 2020-08-07 2022-02-09 Bruker BioSpin GmbH Capteur rmn avec un espace pour échantillon en v pour l'analyse de liquides

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US20200319277A1 (en) 2020-10-08
CA3078574A1 (fr) 2019-04-18
US11143725B2 (en) 2021-10-12
EP3695213A1 (fr) 2020-08-19
DE102017217875A1 (de) 2019-04-25

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